JP2011085464A - Method and device for inspecting baking damage of transparent glass container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To discriminate between baking damage and a joint line with high accuracy to prevent the misjudgment of a good product and a bad product caused by taking the joint line for the baking damage and the misjudgment of the bad product having baking damage and the good product. <P>SOLUTION: In the image of the container imaged by an imaging means with a light source and an imaging means arranged in opposed relationship so as to hold a rotating container to be inspected in between, the lefthand image present on the left side of the axial line of the container and the righthand image present on the right side of the axial line of the container are set. The lefthand image is compared with the righthand image when the surface region of the container corresponding to the lefthand image is present in the righthand image: when there is a dark line in both of the lefthand image and the righthand image, baking damage is judged to be present in the region, and the baking damage and the joint line can be discriminated with high accuracy by judging that no baking damage is present in the region in another case. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a burn inspection method and apparatus for transparent (including translucent) glass bottles capable of detecting with high accuracy defects called burns that occur in the molding process of glass containers such as glass bottles and glass tableware.

A glass container such as a glass bottle is formed by putting a gob (a lump of molten glass) into a rough mold, forming a parison by blowing or pressing, and transferring it to a finishing mold and blowing it.
If there is a scratch or wrinkle on the gob cut out from the orifice, it remains as a streak-like groove in a glass container formed with a finishing die, which is a defect called burn.

Conventionally, as a method for optically inspecting burns, a light source and an imaging unit are arranged to face each other with a rotating container to be inspected, and if there is a dark line in a container image captured by the imaging unit, there is a burn. What to do is known. Since the burn is an approximately V-shaped groove, the light transmitted from the back side to the surface side is dispersed at the portion and appears as a dark line in the container image.
On the other hand, there is a seam line that is unavoidable in forming glass containers such as glass bottles. Since the finish line is a split mold that is divided into two, a slight step is generated at the boundary between the split molds, and is generated almost vertically in the vertical direction.

Conventionally, in order to distinguish between burns and seam lines, the container image captured by the imaging means is processed by software, and when there is a substantially vertical straight dark line, it is determined as a seam line (good product), and others When there is a dark line, it was determined to be burned (defective product).
However, since there are many burned lines that are almost vertical, there are many cases where burns are mistaken for seam lines and misjudged as good products.

Further, in Patent Document 1 below, a striped plate is installed between a light source and a glass container, and a burn or a moiré pattern formed by a striped pattern is used to distinguish between a burn and a joint line. An apparatus is disclosed.
This is because the discontinuous portion of the moire fringes caused by burns is larger than the discontinuous portions caused by the joint lines, so that the difference in size is detected by image processing, and the burns and the joint lines are distinguished. .

Japanese Patent Laid-Open No. 1-129442

  In order to distinguish between burn lines and seam lines, the conventional method using image processing software determines a substantially vertical linear burn as a seam line (good product) as described above. If all the products are not visually inspected, defective products will be put on the market.

  According to the method of Patent Document 1, the moiré fringes of the container image are considerably different due to a slight difference in the thickness distribution of the glass container or a subtle difference in the position of the glass bottle set by the handling device. However, it is difficult to detect discontinuous portions of moire fringes, and there are many misjudgments that make defective products good, which is not realistic. Furthermore, there is also a problem that it is impossible to detect burns in a direction parallel to the striped pattern on the striped plate.

  The present invention distinguishes between burns and seam lines with high accuracy, prevents misjudgment of non-defective products as burnt products by mistakenly misprinting seam lines as burns, and prevents misjudging defective products with burns as good products. It is an object to do.

[Claim 1]
The present invention provides a burn inspection method in which a light source and an imaging unit are arranged opposite to each other with a rotating container to be inspected, and a burn image is detected based on whether there is a dark line in a container image captured by the imaging unit. In the image, a left image on the left side of the container axis and a right image on the right side of the container axis are set, and the left image and the right side when the corresponding region of the container surface is in the right image. A transparent glass container that compares images and determines that there is burns in the area when there is a dark line in both the left image and the right image, and in other cases it is determined that there is no burn in the area This is a burn inspection method.

[Claim 2]
Further, the present invention provides a burn inspection method in which a light source and an imaging unit are arranged opposite to each other with a rotating container to be inspected, and a burn image is detected based on whether there is a dark line in the container image captured by the imaging unit.
In the container image, a center image including the axis of the container, a left image on the left side of the center image, and a right image on the right side are set, and the left image and a region on the container surface corresponding to the left image are set in the center image. Compare the right image when there is a center image at a certain time and the right image, and determine that there is burn in the area when there is a dark line in all these three images, and that there is no burn in the area in other cases It is a burn glass inspection method for a transparent glass container characterized by determining.

[Claim 3]
Further, in the present invention, the distance from the container axis of the left image and the right image is 0.2 W to 0.3 W, where W is the width of the container in the container image. This is a method for inspecting a glass container for burns.

[Claim 4]
Further, the present invention provides a light source, a rotation support means for supporting the container to be inspected while rotating around the axis, an imaging means arranged to face the light source across the container to be inspected, and an image is taken by the imaging means. Processing means for processing a container image, wherein the processing means sets a left image on the left side of the container axis and a right image on the right side of the container axis in the container image, and the left image Compare the right image when the corresponding container surface area is in the right image, and determine that there is burn in the area when there is a dark line in both the left image and the right image. A burn glass inspection apparatus for a transparent glass container, characterized in that it is determined that there is no burn in the area.

[Claim 5]
Further, the present invention provides a light source, a rotation support means for supporting the container to be inspected while rotating around the axis, an imaging means arranged to face the light source across the container to be inspected, and an image is taken by the imaging means. Processing means for processing a container image, the processing means sets a central image including an axis of the container in the container image, a left image on the left side of the central image and a right image on the right side, The left image is compared with the center image when the corresponding container surface area is in the center image, and the right image is compared with the right image when the area is in the right image. It is determined to be present, and in other cases, it is determined that there is no burn in the region.

[Claim 6]
Further, according to the present invention, the distance from the container axis of the left image and the right image is 0.2 W to 0.3 W, where W is the width of the container in the container image. It is a burn inspection device for glass containers.

[Claim 7]
According to the present invention, the light source is a surface light source, and the width of the light emitting surface of the surface light source is 15 ° to 25 ° in plan view opening angle at the intersection of the container to be inspected and the camera axis. It is a burn inspection apparatus of the transparent glass container in any one of.

  In the present invention, “left side” or “right side” means whether it is on the left side or the right side of the container axis when viewed from the imaging means.

[Joint Line]
The principle of the present invention will be described below with reference to the drawings.
FIG. 1 is an enlarged cross-sectional view of a seam line.
As shown in FIG. 1, the seam line 5 generated on the surface of the glass container by the finishing mold seam is stepped, one of which is a steep slope 5a and the other is a gentle slope 5b. . For this reason, when the seam line 5 is on the left side of the container axis, when it is on the right side, or when it is in the center, reflection and refraction of light from the light source are different.

2 and 3 are explanatory diagrams of the relationship between the position of the seam line and the reflected light, and FIG. 4 is an explanatory diagram of the relationship between the position of the seam line and the container image.
The left side of FIG. 4 is a state in which a seam line 5 is on the left side of the container surface, and a region having the seam line is projected on the left side image of the container image. The center of FIG. 4 is a state in which the container is rotated to some extent from the left side, the seam line 5 is in the center of the container surface, and the area having the seam line is projected in the center image of the container image. The right side of FIG. 4 is a state in which the container is further rotated from the center, the seam line 5 is on the right side of the surface of the container, and the area having the seam line is projected on the right image of the container image.

FIG. 2 shows a case where the steep slope 5a of the joint line 5 is on the left side when viewed from the imaging means.
When the joint line 5 is on the left side or the center of the container, the reflected light on the steep slope 5a does not travel in the direction of the imaging means. Further, since the transmitted light diffuses at the seam line part, the amount of light reaching the imaging unit from the seam line part is extremely small, and the seam line becomes a dark line in the container image captured by the imaging unit (the left side and the center in FIG. 4). ).
When the joint line 5 is on the right side of the container, part of the reflected light on the steep slope 5a travels in the direction of the imaging means. The transmitted light is diffused at the seam line portion and the transmitted light reaching the imaging means is reduced, but the reflected light at the steep slope 5a is added, so the seam line is hardly darkened in the container image taken by the imaging means (right side of FIG. 4). ).

FIG. 3 shows a case where the steep slope 5a of the joint line 5 is on the left side when viewed from the imaging means.
In this case, contrary to FIG. 2, when the joint line 5 is on the left side of the container, part of the reflected light on the steep slope 5a travels in the direction of the imaging means. The transmitted light is diffused at the seam line portion and less transmitted light reaches the imaging means, but the reflected light at the steep slope 5a is added, so the seam line is hardly darkened in the container image taken by the imaging means.
Further, when the seam line 5 is on the right side or the center of the container, the reflected light on the steep slope 5a does not travel in the direction of the image pickup means, so the seam line is a dark line in the container image taken by the image pickup means.

  Therefore, the right side image and the left side image of the container images are compared, and if only one of them has a dark line, it can be seen that there is a seam line in the region on the container surface.

(Burn)
FIG. 5 is an enlarged cross-sectional view of the burn 6 and FIG. 6 is an explanatory diagram of the relationship between the burn position and the container image.
The left side of FIG. 6 is a state in which there is a burn 6 on the left side of the container surface, and a burned area is shown in the left image of the container image. The center of FIG. 6 is a state where the container is rotated to some extent from the left side, there is a burn 6 at the center of the container surface, and a burned area is shown in the center image of the container image. The right side of FIG. 6 is a state where the container is further rotated from the center, there is a burn 6 on the right side of the surface of the container, and a burned area is shown in the right image of the container image.

As shown in FIG. 5, the burn is V-shaped, and the slopes 6a and 6b are not smooth but uneven. For this reason, the light from the light source is randomly reflected and refracted by the burn, and the light that reaches the imaging means from the burned portion no matter which part (left side, center, or right side) of the burn is burned The burn image becomes a dark line in the container image picked up by the image pickup means (left side, center and right side in FIG. 6).
FIG. 6 shows the case where the burn is in the vertical direction, but it is exactly the same in the horizontal direction or the inclined burn, and no matter what part of the container (the left side, the central part, or the right side) the burn is. In the container image picked up by the image pickup means, the burn becomes a dark line.

[Distinction between burns and seam lines]
Since it is as described above, the left image and the right image set in the container image are compared, and when both have dark lines, there is a burn in the region of the container surface corresponding to the left image and the right image. The container becomes defective. In addition, when only one of the left image and the right image has a dark line, it can be seen that there is a seam line on the surface of the container corresponding to the left image and the right image.

  When the left image, the center image, and the right image set in the container image are compared and there are dark lines in all of them, there is a burn in the region of the container surface corresponding to these images, and the container becomes a defective product. In addition, when there are dark lines only in the left image and the center image, or only in the center image and the right image, it can be seen that there is a seam line on the container surface in the region corresponding to these images.

In the present invention, the distance from the container axis of the left image and the right image (L, R in FIG. 8) is suitably 0.2 W to 0.3 W, where W is the width of the container in the container image.
If this distance is less than 0.2 W, the seam line that should not be a dark line becomes a dark line, which may be mistaken for a burn. If it exceeds 0.3 W, the area covered by the right side image and the left side image becomes small, which is not practical.

In the present invention, the light source is suitably a surface light source, and the width of the light-emitting surface of the surface light source is suitably 15 ° to 25 ° in terms of the planar opening angle (θ) at the intersection (P) between the container to be inspected and the camera axis. (FIG. 7).
If the opening angle is less than 15 °, a difference in thickness of the glass container tends to appear as a shadow in the image captured by the imaging means, and there is a risk that accurate detection of burns may not be possible. If the opening angle exceeds 25 °, the contrast between the burn and the other part becomes thin, and there is a possibility that the burn cannot be accurately detected.

In the present invention, for example, LED diffuse illumination can be used as the surface light source.
A CCD camera (particularly, a high-speed area camera with a high capture speed) is suitable as the imaging means.
As the rotation support means for supporting the container to be inspected while rotating, a handling apparatus conventionally used in the inspection of glass bottles can be used.
As the processing means, a microcomputer or the like having an image processing function can be used.

  Since the present invention can accurately distinguish between the defect of burns and the seam line, there is very little possibility that the seam line will be mistaken for burns and misjudging a non-defective product as a defective product. The presence or absence of burns can be detected with high accuracy.

It is an expanded sectional view of a joint line. It is explanatory drawing of the relationship between the position of a joint line, and reflected light. It is explanatory drawing of the relationship between the position of a joint line, and reflected light. It is explanatory drawing of the relationship between the position of a joint line, and a container image. It is an expanded sectional view of a burn. It is explanatory drawing of the relationship between the position of a burn, and a container image. It is the top view and side view of a burn inspection apparatus of an Example. It is explanatory drawing of the relationship between the area | region of a glass container surface, and an image. It is explanatory drawing of the relationship between the area | region of the surface of the rotating glass container, and an image.

FIG. 7 is a schematic plan view (upper stage) and side view (lower stage) of the burn inspection apparatus of the embodiment.
The glass container 1 (glass bottle) is supported by a rotation support means (not shown) and undergoes a burn inspection while rotating.
A light source 2 (surface light source) and an image pickup means 3 (high-speed area camera) are arranged to face each other with the glass container 1 interposed therebetween. The width of the light emitting surface 2a of the surface light source 2 of the present embodiment is as follows: the plane opening angle θ = 20 ° at the intersection P (the point farthest from the light source on the outer peripheral surface of the glass container) Is the width. Processing means 4 (microcomputer) is connected to the imaging means 3.

FIG. 8 is an explanatory diagram of the relationship between the area on the surface of the glass container and the image.
The processing means 4 sets the left image, the center image, and the right image in the entire image of the captured glass container (or the entire image of the body when inspecting only the body). For this setting, an image section (position / size) to be set in advance in the processing means may be registered in coordinates.
In this embodiment, the distance L from the container axis to the left image and the distance R from the right image are both about 0.25 W (W is the width of the container in the container image = diameter).

FIG. 8 shows a region on the surface of the container when the imaging unit first releases the shutter and captures the first image.
At this time, although it is virtual, a total of 12 regions of A1 to A6 and B1 to B6 are formed on the container surface.
In FIG. 8, the A3 area is shown in the left image, the A2 area is shown in the center image, and the A1 area is shown in the right image (first image in FIG. 9).

From the state of FIG. 8, every time the glass container rotates 60 ° in the direction of the arrow, the image is picked up by the image pickup means 3 and the sixth image is picked up. Thereafter, the seventh image is picked up when the glass container is rotated by 90 °, and up to the twelfth image is picked up every time the glass container is further rotated by 60 °.
The captured first to twelfth images are stored in the memory of the processing means, and a left image, a center image, and a right image are extracted and set for each image.

FIG. 9 shows areas projected on the left image, the center image, and the right image in the first to twelfth images.
The A1 to A6 regions of the glass container are projected on the left image, the center image, and the right image of the first to sixth images, and the left image, the center image, and the right image of the seventh to twelfth images are Areas B1 to B6 are projected.

The processing means 3 inspects whether all areas A1 to A6 and B1 to B6 have burns from the left image, the center image, and the right image of the first to twelfth images.
For example, when inspecting the A1 area, the right image of the first image, the left image of the fifth image, and the center image of the sixth image are compared, and if all these images have dark lines, it is determined that there is burn in the A1 area. In other cases, it is determined that there is no burn in the A1 area.
For example, when inspecting the B4 region, the left image of the eighth image, the center image of the ninth image, and the right image of the tenth image are compared.
Whether or not each image has a dark line is determined based on a preset brightness threshold of the pixel.

  When the processing means 4 determines that there are no burns for all areas A1 to A6 and B1 to B6, the glass container is determined to be non-defective, and if any one or more areas are determined to have burns, The glass container is determined to be defective, and a defect signal is sent to the handling device to remove the glass container from the inspection line.

  8 and 9 show the burn inspection of the body of the glass container, but the left image, the center image, and the right image can be set for the shoulder portion and the neck portion, and the inspection can be performed in the same manner.

  8 and 9 set the left image, the center image, and the right image for each container image, but only the left image and the right image can be set and inspected. In that case, the right side image and the left side image are compared for all regions A1 to A6 and B1 to B6. judge.

DESCRIPTION OF SYMBOLS 1 Glass container 2 Light source 2a Light emission surface 3 Imaging means 4 Processing means 5 Eye line 6 Burn

Claims (7)

In the burn inspection method in which the light source and the image pickup means are arranged opposite to each other with the rotating container to be inspected, and the container image picked up by the image pickup means detects a burn if there is a dark line,
In the container image, a left image on the left side of the container axis and a right image on the right side of the container axis are set, and the left image and the corresponding container surface area are in the right image. The right side image is compared, and when there is a dark line in both the left side image and the right side image, it is determined that there is burn in the region, and in other cases, it is determined that there is no burn in the region. Burn inspection method for glass containers. In the burn inspection method in which the light source and the image pickup means are arranged opposite to each other with the rotating container to be inspected, and the container image picked up by the image pickup means detects a burn if there is a dark line,
In the container image, a central image including the axis of the container, a left image on the left side of the central image and a right image on the right side are set.
The left image is compared with the center image when the corresponding container surface area is in the central image, and the right image is compared with the right image when it is in the right image. A burn inspection method for a transparent glass container, characterized in that it is determined that there is a scratch and in other cases it is determined that there is no burn in the region.   The burn of the transparent glass container according to claim 1 or 2, wherein the distance from the container axis of the left image and the right image is 0.2W to 0.3W, where W is the width of the container in the container image. Inspection method. A light source;
Rotation support means for supporting the inspected container while rotating around the axis;
Imaging means arranged opposite to the light source across the container to be inspected;
Processing means for processing the container image imaged by the imaging means;
The processing means sets, in the container image, a left image on the left side of the container axis and a right image on the right side of the container axis, and the left image and a corresponding region on the container surface are Compare the right image when it is in the right image, and determine that there is burn in the area when there are dark lines in both the left image and the right image, and in other cases, determine that there is no burn in the area A burn glass inspection device for transparent glass containers. A light source;
Rotation support means for supporting the inspected container while rotating around the axis;
Imaging means arranged opposite to the light source across the container to be inspected;
Processing means for processing the container image imaged by the imaging means;
The processing means sets a central image including the axis of the container in the container image, a left image on the left side of the central image, and a right image on the right side,
The left image is compared with the center image when the corresponding container surface area is in the central image, and the right image is compared with the right image when it is in the right image. A burn inspection apparatus for a transparent glass container, characterized in that it is determined that there is a scratch, and in other cases it is determined that there is no burn in the region.   6. The transparent glass container according to claim 4 or 5, wherein the distance from the container axis of the left image and the right image is 0.2W to 0.3W, where W is the width of the container in the container image. Inspection device.   The light source is a surface light source, and the width of the light emitting surface of the surface light source is 15 ° to 25 ° in plan view opening angle at the intersection of the container to be inspected and the imaging means axis. The burn inspection apparatus of the transparent glass container as described.

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